fix (kubernetes-model-generator) : Handle deserialization of defaultMode field in custom deserializers for VolumeSource types

[rohanKanojia]

Description

Fix #6110

Jackson doesn't properly handle deserialization of octal integer value in YAML

• Hex number as an entry of an Object causing problem(s) with binding to POJO FasterXML/jackson-dataformats-text#71
• Support decoding Binary, Octal and Hex numbers as integers FasterXML/jackson-dataformats-text#233
• (yaml) Does not handle octal or hexadecimal representations of integers FasterXML/jackson-dataformats-text#3

Jenkins Kubernetes Plugin team also faced some issues for octal handling, here is the linked PR jenkinsci/kubernetes-plugin#1503

Add custom deserializers to handle correct octal deserialization for these types:

• ConfigMapVolumeSource
• SecretVolumeSource
• DownwardAPIVolumeSource
• ProjectedVolumeSource

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change
• Chore (non-breaking change which doesn't affect codebase;
  test, version modification, documentation, etc.)

Checklist

• Code contributed by me aligns with current project license: Apache 2.0
• I Added CHANGELOG entry regarding this change
• I have implemented unit tests to cover my changes
• I have added/updated the javadocs and other documentation accordingly
• No new bugs, code smells, etc. in SonarCloud report
• I tested my code in Kubernetes
• I tested my code in OpenShift

[sonarcloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
88.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[manusa]

LGTM, thx!